Sako, 64, is replacing retired Emmanuel III Delly, 85, who became Iraq's first cardinal when he was elevated by Benedict in 2007.

Bishops of the Eastern rite church chose Sako, archbishop of Kirkuk since 2003, as their patriarch earlier this week.

"I will do my best to serve the Iraqi people," Sako said Friday. "I hope peace and security will prevail in my country."

In the aftermath of the 2003 U.S. invasion of Iraq, Delly urged the country's 1.5 million Christians to stay in the Arab country even as sectarian attacks launched by Islamic militants surged. Nonetheless, hundreds of thousands of fearful Iraqi Christians have gone abroad.

Sako was ordained in 1974, earned two doctorates in Rome and Paris in the 1980s and then returned to Iraq, the Vatican said. He has written books on church fathers. He speaks Arabic, Chaldean, French, English and Italian.